Sequential 'Flooding' Puts Video Surveillance Systems to the Test
Editor's note: Following Wuhan and Beijing, it is Changsha's turn to be "flooded." At noon on the 28th, a torrential rainstorm struck Changsha, Hunan. After successfully withstanding multiple rounds of "rainstorm assaults" since June, Changsha's drainage system ultimately "succumbed," leaving many urban areas with deep water accumulation and traffic in chaos. Amid this unprecedented flood, can the video surveillance systems in urban subways continue to operate normally? With sequential "flooding," video surveillance systems are being put to a severe test.
As the rainstorm hit, netizens in Changsha were not idle either. Jokes such as "Everyone has a sea-view room" and "Changsha finally has a 'sea' to look at" appeared on Weibo and various online forums, with netizens describing this as an optimistic attitude toward the flood. Wuhan, Beijing, and other cities have all experienced urban flooding caused by torrential rains.
Sequential "Flooding" Puts Video Surveillance Systems to the Test
Beijing: Strengthening waterproofing of subway cameras to ensure normal operation of the entire system
Currently, the waterproofing standard adopted for Beijing subway surveillance cameras is based on the IP (Ingress Protection) rating system. The IP protection standard classifies electrical appliances according to their dust and moisture resistance. The foreign objects referred to here include tools, human fingers, etc., which must not come into contact with live parts inside the appliance to prevent electric shock. The IP protection rating consists of two digits: the first digit indicates the level of protection against dust and foreign object intrusion, while the second digit indicates the degree of sealing against moisture and water intrusion. The higher the number, the higher the protection level. It is understood that the current waterproofing standard for outdoor cameras is IP66, which is the sixth level of waterproofing, meaning "protection against heavy seas, or protection of equipment installed on deck against damage caused by the ingress of water from heavy seas."
Coincidentally, just days before Beijing's subway was hit by floodwaters, Shenzhen's subway Airport East Station experienced a similar situation of "heavy rain outside, light rain inside," once again raising questions about the waterproofing requirements of indoor video surveillance systems. In my view, given the frequent water ingress in many urban subway projects, security companies should also raise the waterproofing standards for indoor surveillance cameras and pay greater attention to this issue. When one door closes, another opens — since subway project waterproofing is a concern, strengthening camera waterproofing is the only way to ensure the entire system can operate normally.
Zigong: Strengthening monitoring of geological hazard-prone areas
Following the issuance of a yellow rainstorm warning signal on the evening of the 19th, from daytime on June 20th to around 7 a.m. on the 21st, Zigong experienced a thunderstorm weather process. Parts of the central and western regions received moderate to heavy rain, with the maximum rainfall recorded at Honghua Plant reaching 40.3 mm. According to the latest meteorological data analysis, rainfall is expected to continue. It is forecast that from the night of the 21st to the night of the 22nd, Zigong will experience a rainstorm weather process, accompanied by gusty winds of force 4 to 5 during thunderstorms. The meteorological geological hazard level in the western and northeastern parts of the city is rated at 4 to 5. Relevant units and the general public are advised to take precautions against the hazards of thunderstorms, heavy rain, and strong winds, and to strengthen monitoring of geological hazard-prone areas.
Qingdao: Full monitoring of urban road water accumulation, with 8 LCD screens in operation
To ensure roads remain free of water accumulation, the Municipal Drainage Management Office has conducted a comprehensive inspection of all drainage facilities in the four urban districts in advance. At the supervision and service center of the Drainage Management Office, 8 LCD screens are in operation. Director Yang of the supervision and service center told reporters that this system is networked with the traffic police department's video monitoring, enabling real-time monitoring of flood prevention conditions at more than 200 key roads and over 400 points across the city. The Municipal Drainage Management Office has also deployed 49 flood prevention vehicles to conduct uninterrupted patrols of key road sections during rainfall. Staff of the Municipal Drainage Management Office explained that for such key flood prevention locations, they have specifically established a dedicated personnel on-duty plan during rainfall, opening drainage grates and setting up drainage barriers to ensure traffic safety.
During heavy rain, how to prevent lightning from "visiting" surveillance systems
According to the annual lightning protection inspection data published by the Beijing Lightning Protection Device Safety Testing Center, the pass rate for direct lightning protection testing of building structures across the city exceeds 90%, yet the pass rate for indirect lightning protection testing of electronic systems inside buildings is less than half. In lightning disasters in recent years, over 80% of damage has been to internal equipment, including electrical appliances, surveillance systems, and probes. Some high-tech electronic devices have very weak anti-interference capabilities. For example, surveillance probes and intercom systems in some residential communities have no lightning protection devices at all, making them vulnerable to induced lightning that can easily penetrate and destroy the system. By implementing proper lightning protection for front-end equipment, transmission lines, and monitoring centers, there will be no need to worry about lightning strikes on the system.
Related reading: With continuous torrential rain, can urban construction retain low-lying open spaces?
Several major cities have been hit by torrential rains — Wuhan, Changsha, Beijing — and after the storms, streets and urban areas looked like flooded marshlands. This is not unique to this year. Cities cannot withstand torrential rain. Can our urban construction retain low-lying open spaces? Especially in those cities prone to rainstorms. According to reports, a city in the United States once experienced heavy rain, and the moment the downpour stopped, the ground was instantly free of water accumulation. It turned out that all the rainwater had quickly converged into a low-lying area near the residential district, enclosed by wire fencing. Of course, one cannot help but admire that the United States has a sparse population and vast land, with large open spaces and parking lots within cities. Chinese cities compete for every inch of land, resulting in concrete jungles everywhere, lacking green spaces and wetlands. With continuous torrential rain, can urban construction retain low-lying open spaces? (China Security & Protection Exhibition Network)